Catheter ablation of the cavotricuspid isthmus in patients with atrial flutter: Predictors of long-term outcomes

Abstract

Background: Predictors of long-term outcomes and an optimal catheter set for ablation of the cavotricuspid isthmus in patients with atrial flutter (AFL) are not well known. Aims: This study aimed to identify predictors of clinical events following ablation. Methods: We studied 741 patients (mean [SD] age, 62.2 [10.8] years; 248 women) who were followed for a mean (SD) time of 4.4 (2.7) years. The 2- versus 3-electrode approach and clinical predictors of clinical events during follow -up were analyzed. Results: The 2-electrode approach was faster (mean [SD] time, 62.5 [30.3] vs 101.4 [51] min; P <0.001), associated with shorter fluoroscopy time (13.1 [9.3] vs 20.3 [12.4] min; P < 0.001), cost-effective (8.29 [2.82] vs 11.89 [2.51] units; P <0.001), and more effective (92.1% vs 86.1%; P = 0.012). The independent predictors of AFL recurrence were: calcium blocker use (hazard ratio [HR], 3.24; 95% CI, 1.64-6.4), mitral valve disease (HR, 1.82; 95% CI, 1.12-2.95), previous stroke and / or TIA (HR, 2.38; 95% CI, 1.21-4.65), pulmonary artery dilatation (HR, 3.94; 95% CI, 1.22-12.73), and previous pulmonary embolism (HR, 3.77; 95% CI, 1.14-12.43); of atrial fibrillation (AF): previous AF (HR, 6.054; 95% CI, 4.58-8), left atrial enlargement (HR, 1.43; 95% CI, 1.12-1.81), number of antiarrhythmic drugs used (HR, 1.16; 95% CI, 1.05-1.28), and mitral valve disease (HR, 1.28; 95% CI, 1.04-1.58); of pacemaker implantation: tachycardia-bradycardia syndrome (HR, 6.17; 95% CI, 3.16-12.05), previous second-/third-degree atrioventricular block (HR, 29.4; 95% CI, 7.37-117.28), centrally acting hypotensive drugs (HR, 29.55; 95% CI, 6.14-142.25), aortic dilatation or aneurysm (HR, 2.58; 95% CI, 1.06-6.3), a labile international normalized ratio (HR, 3.45; 95% CI, 1.72-6.93), left bundle branch block (HR, 4.7; 95% CI, 1.49-14.82), the shortest R-R interval during AFL (HR, 1.003; 95% CI, 1.001-1.005), previous cardiac surgery (HR, 2.69; 95% CI, 1.27-5.7), and aortic valve disease (HR, 2.22; 95% CI, 1.08-4.59). Conclusions: Ablation of cavotricuspid isthmus with a minimal number of electrodes is safe and effective. Specific predictors of clinical events during long-term follow-up can be determined.